Downwind turn Myth
#1426
Please, enlighten us, cite a reference for that. My -182 stalled at 51 MPH no power full flaps. My -182 full power, full flaps wouldn't stall at all. STOL conversion kit, No stall is a function of angle of attack, g loading and power.
#1428
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As a CFI with 1000hrs of dual given, i spent many hundreds of hours doing exactly what he stated. I remember one day i was with a student in a C152 at 8,000' msl. With a headwind at vso +5 we had a ground speed of negative 15kts. The lesson for the day was slow speed manuevering. 90* turns no problem, 180* turns didnt result in any indicated airspeed change, but a descent rate Would be noticed IF the student did not anticipate or correct with the application of More power.
Point being, indicated airspeed doesnt change if all things are kept equal throughout the turn, ground speed will increase as the turn to downwind is completed, rate of climb/descent will change.
#1429
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May I assume the the banks were shallow and that every control input was done gently? That's how my CFI worked slow flight with me. I think RC pilots assume that they can continue to yank and bank regardless of how close they are to the critical angle of attack.
Jaybird
p.s. Slow flight is quite a challenge and fun with both full size and models especially when your reserve power is limited.
Jaybird
p.s. Slow flight is quite a challenge and fun with both full size and models especially when your reserve power is limited.
#1430
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May I assume the the banks were shallow and that every control input was done gently? That's how my CFI worked slow flight with me. I think RC pilots assume that they can continue to yank and bank regardless of how close they are to the critical angle of attack.
Jaybird
p.s. Slow flight is quite a challenge and fun with both full size and models especially when your reserve power is limited.
Jaybird
p.s. Slow flight is quite a challenge and fun with both full size and models especially when your reserve power is limited.
#1431
Newton did not do all of his calculations from the center of the earth. He had a theory of relativity. But, you are several centuries out of date. Einstein took that and added so much more to his theory and made it his own with his "special" and "general" theories of relativity.
#1432
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Ill admit, I dont understand much on this topic, but if what you say is true then why do EDF jets trying to break there speed records have to make passes up and down wind to count if the wind direction has no effect? But we usly see a slightly slower ground speed from one of the runs
#1433
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As a CFI with 1000hrs of dual given, i spent many hundreds of hours doing exactly what he stated. I remember one day i was with a student in a C152 at 8,000' msl. With a headwind at vso +5 we had a ground speed of negative 15kts. The lesson for the day was slow speed manuevering. 90* turns no problem, 180* turns didnt result in any indicated airspeed change, but a descent rate Would be noticed IF the student did not anticipate or correct with the application of More power.
Point being, indicated airspeed doesnt change if all things are kept equal throughout the turn, ground speed will increase as the turn to downwind is completed, rate of climb/descent will change.
Point being, indicated airspeed doesnt change if all things are kept equal throughout the turn, ground speed will increase as the turn to downwind is completed, rate of climb/descent will change.
#1434
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Newton did not do all of his calculations from the center of the earth. He had a theory of relativity. But, you are several centuries out of date. Einstein took that and added so much more to his theory and made it his own with his "special" and "general" theories of relativity.
I am certain he never said acceleration depends on which way the wind blows
Last edited by dirtybird; 09-08-2015 at 12:23 PM.
#1435
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As a CFI with 1000hrs of dual given, i spent many hundreds of hours doing exactly what he stated. I remember one day i was with a student in a C152 at 8,000' msl. With a headwind at vso +5 we had a ground speed of negative 15kts. The lesson for the day was slow speed manuevering. 90* turns no problem, 180* turns didnt result in any indicated airspeed change, but a descent rate Would be noticed IF the student did not anticipate or correct with the application of More power.
Point being, indicated airspeed doesnt change if all things are kept equal throughout the turn, ground speed will increase as the turn to downwind is completed, rate of climb/descent will change.
Point being, indicated airspeed doesnt change if all things are kept equal throughout the turn, ground speed will increase as the turn to downwind is completed, rate of climb/descent will change.
#1436
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#1438
I don't think that you understand that Newton had his own theory of relativity that did not include the speed of light or space-time. His theory would explain why a plane flying a high g circle would make a circle when viewed from a balloon and an elapse when traced on the ground.
#1439
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Why not? I've seen model planes hold altitude in a strong wind and move backwards relative to where I'm standing. I've read stories in the flying magazines (AOPA, Flight Journal) of passengers in a Piper Cub watching the trees and ground moving forward on an especially windy day. If the wind is blowing 50 mph and the plane you are in can do slow flight at 45 mph then the airmass you are flying in will move you backwards at 5 mph.
Jaybird
Jaybird
#1442
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Why not? I've seen model planes hold altitude in a strong wind and move backwards relative to where I'm standing. I've read stories in the flying magazines (AOPA, Flight Journal) of passengers in a Piper Cub watching the trees and ground moving forward on an especially windy day. If the wind is blowing 50 mph and the plane you are in can do slow flight at 45 mph then the airmass you are flying in will move you backwards at 5 mph.
Jaybird
Jaybird
Even if he was right on the stall, he would need a 55 knot headwind to go backwards at 15 knots. That's a 63 MPH headwind at the very minimum without falling out of the sky.
Take everything you read with a grain of salt.
#1444
It makes me laugh when some compare models to full size planes.
Even if he was right on the stall, he would need a 55 knot headwind to go backwards at 15 knots. That's a 63 MPH headwind at the very minimum without falling out of the sky.
Take everything you read with a grain of salt.
Even if he was right on the stall, he would need a 55 knot headwind to go backwards at 15 knots. That's a 63 MPH headwind at the very minimum without falling out of the sky.
Take everything you read with a grain of salt.
#1445
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The most basic understanding of aerodynamics and performance dictates that airspeed does Not change with regard to the airmass in which it is flying unless pitch or power has been altered.
#1446
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#1447
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Hey, Jaybird!
How are things back home? I'm from Newport/Plymouth area. In fact, the cub I mentioned crashing due to a downwind turn crashed on Plymouth Pond in the middle of winter, I think the year was 1991.
Jim
How are things back home? I'm from Newport/Plymouth area. In fact, the cub I mentioned crashing due to a downwind turn crashed on Plymouth Pond in the middle of winter, I think the year was 1991.
Jim
#1448
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so the way I understand the argument is if you are traveling up wind going 60mph and the wind is 20mph you are traveling 40mph ground speed and you turn down wind and now have to have sufficient airspeed to allow the plane to accelerate up to the 80mph ground speed before you stall, due to the momentum. lets look at it logically. what causes the GS to be different than the AS? You are flying north at 60mph and the wind is moving south at 20mph. 60-20=40, therefore you are flying 40mph GS. now lets say you are flying south at 60 and the wind is moving south at 20. 60+20=80, therefore 80mph GS. so you can look at it this way, and any physics professor will agree, in relation to the ground you are traveling 20mph south all the time. this can be seen by the need to crab on cross wind. you are traveling 60mph AS the whole time as well. so we can agree that the airplane upwind has 60mph worth of momentum through the air northbound and 20mph worth of momentum southbound equaling 40mph of momentum. heading south the plane has 60mph of momentum to the south and the wind has 20mph of momentum to the south equaling 80mph of momentum to the south. do you see the constant here? the wind is always providing that 20mph worth of energy to the south and the plane is providing the 60mph worth of energy so if you add energy by throttling up you will have excess energy. there is no change in momentum due to the wind when changing direction. the only part that could account for that would be the turn and that, if flown the same, is identical with or without wind. anyone still doubting it run this by a physics professor and see what they say.
#1449
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The error of that hypothesis as I see it is you are relating momentum to the wind. Momentum is related to the earth not the wind.
I don't know any Physics profs but I know some fellow aerodynamic engineers at Boeing. I will run it by them
I don't know any Physics profs but I know some fellow aerodynamic engineers at Boeing. I will run it by them